1. Field of the Invention
This invention relates to an air intake apparatus for use in a diesel engine, and more particularly to an air intake apparatus for use in a spark-assisted diesel engine wherein ignition of the fuel injected into its cylinders is assisted by spark. In the spark assisted diesel engines of the kind specified above, a mixed fuel containing more than 10% by volume of methanol or ethanol is used as its fuel, and also an oxidation catalyst is disposed in its exhaust pipe.
2. Description of the Prior Art
In the previously produced air intake apparatus for use in the diesel engines of the kind specified, no adjustment has been made to reduce the amount of air intake when the engine is running under an idling condition or under a low load condition, that is, a partial load condition, or even if such an adjustment has been made, it has not always been satisfactory to meet the requirements.
Therefore, in the spark-assisted diesel engines provided with the previously produced air intake apparatus, perfect combustion of the fuel injected into cylinders thereof cannot be achieved under partial load condition, thus giving ill influence on the fuel consumption rate and the characteristics of exhaust gas.